If you are having this problem, maybe I could help you with that.
I know facing smurf could be annoying sometimes but let me assure you that playing arena isn't mandatory for low rank (atleast for me). I was facing the same problem as you but with a bit more farming in campaign, you can upgrade your mech even better. It is not like you are hardstuck rank 15 or whatever, you can still "quit" when you facing one of those players.
The smurfer usually camping on rank 17 - 15, but you can still find players that have the same mech as you, you just need luck. And ranking up in low rank is not that hard, you just need I believe 3 or 4 to rank up.
Recap, if you dont find yourself having fun in arena, maybe just dont play arena at all, just finish the daily and call it the day. Farm campaign, get more boxes and start upgrading your mech.